Conversion of aromatics over novel catalyst composition

ABSTRACT

Feedstock comprising aromatic compounds is converted by isomerization, alkylation, disproportionation or transalkylation to product comprising aromatic compounds which differs from the feedstock over catalyst having been prepared by reacting a high-silica zeolite with an acidic inorganic oxide in the presence of water.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 792,346, filed Oct. 29,1985, now U.S. Pat. No. 4,665,253 which is a continuation-in-part ofapplication Ser. No. 620,365, filed June 13, 1984, now U.S. Pat. No.4,563,435, which is a continuation-in-part of application Ser. No.391,212, filed June 23, 1982, now abandoned.

BACKGROUND OF THE INVENTION

1. Field Of The Invention

This invention relates to use of crystalline silicates having a highsilica/alumina mole ratio. In one aspect of this invention a novelcatalyst composition is prepared from said high silica materials byreacting the same with certain binders such as an alumina-containingbinder, and in another aspect of this invention conversion processes arecarried out with said novel catalyst composition. In particular, theinvention relates to conversion of feedstock comprising aromaticcompounds to product comprising aromatic compounds which differs fromthe feedstock.

2. Description Of The Prior Art

High silica/alumina mole ratio crystalline silicates are well known inthe art and it is generally accepted that the ion exchange capacity ofsuch crystalline silicates is directly dependent on the amount of metalwhich is tetrahedrally coordinated with the silica in the framework.Thus, for example, with regard to the most common zeolitic crystallinematerials; namely, crystalline aluminosilicate zeolites, such materialcan be described as a rigid three dimensional network of SiO₄ and AlO₄in which the tetrahedra are cross-linked by the sharing of oxygen atomswhereby the ratio of total aluminum and silicon atoms to oxygen is 1:2.The electrovalence of the tetrahedra-containing aluminum is balanced bythe inclusion in the crystal of a cation. Quite obviously, the morealuminum that is present in the crystal the more cations can beintroduced into the crystalline structure. Recently, the scientific andtechnical literature has disclosed high silica-containing zeoliticstructures wherein substantially all or a portion of the aluminumpresent in the crystal framework has been replaced by other metalseither partially or completely. Thus, for example, iron, chromium andboron are materials which have been described in the prior art ascapable of being substituted for aluminum in the crystal framework andquite obviously, the ion exchange capacity of the resulting zeoliticstructure will again be determined by the amount of metal which is intetrahedral coordination with the silica. Thus, for example, the moreboron there is in a crystalline structure, the more cations are requiredto balance the electronegativity thereof and when such cations are ofthe acidic type, such as hydrogen, they impart tremendous catalyticactivity to the crystalline material. On the other hand, crystallinesilicates having a high silica/alumina mole ratio of greater than about1600 have many important properties and characteristics and have a highdegree of structural stability such that they have become candidates foruse in various processes, incuding catalytic processes. Materials ofthis type are well known in the art and include high silica-containingaluminosilicates such as ZSM-5 (U.S. Pat. No. 3,702,886), ZSM-11 (U.S.Pat. No. 3,709,979), and ZSM-12 (U.S. Pat. No. 3,832,449) to mention afew. It is also known in the art that the silica/alumina ratio of agiven zeolite is often variable. For example, zeolite X can besynthesized with a silica/alumina ratio of from 2 to 3 and zeolite Yfrom about 3 to about 6. In some zeolites, the upper limit ofsilica/alumina ratio is virtually unbounded. Zeolite ZSM-5 is one suchmaterial wherein the silica/alumina ratio is at least 5. U.S. Pat. No.3,941,871 discloses a crystalline metallo-aluminosilicate essentiallyfree of aluminum and exhibiting an X-ray diffraction patterncharacteristic of ZSM-5. U.S. Pat. Nos. 4,061,724; 4,073,865; and4,104,294 describe microporous crystalline silicas wherein the aluminumcontent is present at very low levels. Because of the extremely lowaluminum content of these high silica-containing zeolites there ionexchange capacity is not as great as materials with a higher aluminumcontent. Therefore, when these materials are contacted with an acidicsolution and thereafter are processed in a conventional manner, they arenot as catalytically active as their higher aluminum containingcounterparts. This invention permits the preparation and use of certainhigh silica-containing materials which have all the desirable propertiesinherently possessed by such high silica materials and yet have an acidactivity which has heretofore only been possible to be achieved bymaterials having a higher aluminum content in their "as synthesized"form or by certain activation techniques, such as treatment withmetallic vapors.

U.S. Pat. No. 4,380,685 teaches para-selective alkylation,transalkylation or disproportionation of a substituted aromatic compoundto form a dialkylbenzene compound mixture over catalyst comprisingzeolite characterized by a constraint index of 1 to 12 and asilica:alumina mole ratio of at least 12:1, the catalyst havingincorporated therein various metals and phosphorus. Other parentscovering alkylation and transalkylation include U.S. Pat. Nos.4,127,616, 4,361,713, 4,365,104, 4,367,359, 4,370,508 and 4,384,155.Toluene is converted to para-xylene in U.S. Pat. Nos. 3,965,207,3,965,208, 3,965,209, 4,001,346, 4,002,698, 4,067,920, 4,100,125 and4,152,364, to name a few. Alkylation with olefins is taught, forexample, in U.S. Pat. Nos. 3,962,364 and 4,016,218 and toluene isdisproportionated in, for example, U.S. Pat. Nos. 4,052,476, 4,007,231,4,011,276, 4,016,219 and 4,029,716. Isomerization of xylenes is taughtin, for example, U.S. Pat. Nos. 4,100,214, 4,101,595, 4,158,676,4,159,282, 4,351,979, 4,101,597, 4,159,283, 4,152,353, 4,163,028,4,188,282 and 4,224,141.

SUMMARY OF THE INVENTION

The present invention relates to use of a high silica crystallinematerial having improved acid activity such as, for example, catalyticcracking and dewaxing activity, as a result of reaction of said highsilica material with an acidic inorganic oxide, e.g alumina. Thereaction requires mixing said high silica material with an acidicinorganic oxide in the presence of water, forming or shaping the mixtureinto a desired shape, and then calcining the formed or shaped mixture atan elevated temperature.

It has been found that it is absolutely crucial in this invention thatthe inorganic oxide, e.g. alumina, and the crystalline high silicamaterial be physically admixed in the presence of water. If thematerials are added in a completely dry state, absolutely no activationtakes place irrespective of whether or not the later processing stepsare carried out. In a particular preferred embodiment of this invention,the high silica zeolite and alumina are extruded under hydraulicpressures ranging from about 2 to about 50 tons per square inch (t/in²).For reasons which are not completely understood, it has been found thatthe extrusion step under high pressure imparts even a greater activationto the high silica zeolitic material.

EMBODIMENTS

The present invention provides a process for converting feedstockcomprising aromatic compounds selected from the group consisting ofbenzene and monocyclic alkyl-substituted benzene of from 7 to 10 carbonatoms to product comprising aromatic compounds which differs from saidfeedstock, examples of which include isomerizing xylene feedstockcomponents to product enriched in p-xylene with reaction conditionsincluding a temperature from about 230° C. to about 510° C., a pressureof from about 3 atmospheres to about 35 atmospheres, a weight hourlyspace velocity of from about 0.1 hr⁻¹ to about 200 hr⁻¹ and ahydrogen/hydrocarbon mole ratio of from 0 (no added hydrogen) to about100; disproportionating toluene to product comprising benzene andxylenes with reaction conditions including a temperature of from about200° C. to about 760° C., a pressure of from about atmospheric to about60 atmospheres and a weight hourly spaced velocity of from about 0.08hr⁻¹ to about 20 hr⁻¹ ; alkylating aromatic hydrocarbons, e.g. benzeneand C₇ and C₈ alkylbenzenes, in the presence of an alkylating agent,e.g. olefins, formaldehyde, alkyl halides and alcohols, with reactionconditions including a temperature of from about 340° C. to about 500°C., a pressure of from about atmospheric to about 200 atmospheres, aweight hourly spaced velocity of from about 2 hr⁻¹ to about 2000 hr⁻¹and an aromatic hydrocarbon/alkylating agent mole ratio of from about1/1 to about 20/1; and transalkylating aromatic hydrocarbons in thepresence of polyalkylaromatic hydrocarbons with reaction conditionsincluding a temperature of from about 340° C. to about 500° C., apressure of from about atmospheric to about 200 atmospheres, a weighthourly space velocity of from about 10 hr⁻¹ to about 1000 hr⁻¹ and anaromatic hydrocarbon/polyalkylaromatic hydrocarbon mole ratio of fromabout 1/1 to about 16/1.

Reaction conditions for conversion of aromatics as above-detailedinclude, in general, a temperature of from about 200° C. to about 760°C., a pressure of from about atmospheric to about 200 atmospheres, aweight hourly space velocity of from about 0.08 hr⁻¹ to about 2000 hr⁻¹,and a hydrogen/feedstock aromatic hydrocarbon mole ratio of from 0 (noadded hydrogen) to about 100.

Feedstock aromatic compounds converted hereby include individually andin mixture benzene and monocyclic alkyl-substituted benzene of from 7 to10 carbon atoms having the structure ##STR1## where R is methyl, ethylor a combination thereof, and n is an integer of from 1 to 4. In otherwords, the feedstock aromatic compounds may be benzene, benzenecontaining from 1 to 4 methyl and/or ethyl group substituents, andmixtures thereof. Non-limiting examples of such feedstock compoundsinclude benzene, toluene, xylene, ethylbenzene,mesitylene(1,3,5-trimethylbenzene), durene(1,2,4,5-tetramethylbenzene),pseudocumene(1,2,4-trimethylbenzene) and mixtures thereof.

Other reactants species may be present, such as for alkylation.Alkylating agent species include olefins such as ethylene, propylene,dodecylene, as well as formaldehyde, alkyl halides and alcohols; thealkyl portion thereof having from 1 to 24 carbon atoms. Numerous otheracyclic compounds having at least one reactive alkyl radical may beutilized as alkylating agents.

Products of the present conversion process include alkyl-substitutedbenzene compounds which differ from feedstock compounds depending uponthe conversion desired. The following listing presents non-limitingexamples:

    ______________________________________                                        Feedstock               Product                                               Aromatic      Other     Aromatic                                              Compounds     Reactants Compounds                                             Include       Include   Include                                               ______________________________________                                        Benzene       Ethylene  Ethylbenzene                                          Toluene       Methanol  Xylene isomers                                        Xylene        --        Different                                             isomers, e.g.,          combination of xylene                                 9:73:18 wt. ratio       isomers, e.g. 23:57:20                                of para:meta:ortho      wt. ratio of                                                                  para:meta:ortho                                       Toluene       --        Benzene and xylenes                                   Benzene       Propylene Cumene and                                                                    diisopropylbenzene                                    Toluene       Propylene Cymene isomers                                        ______________________________________                                    

Mechanisms of the present process may be isomerization, alkylation,transalkylation and disproportionation. Disproportionation is a specialcase of transalkylation in which the alkylatable aromatic compound andthe transalkylating agent is the same compound, for example, whentoluene serves as the doner and acceptor of the transferred methyl groupto produce benzene and xylene. Use of the term transalkylation includesthe special case of disproportionation.

This invention is concerned with use of high silica-containingcrystalline materials. The expression "high silica-containingcrystalline material" is intended to define a crystalline structurewhich has a silica/alumina mole ratio greater than about 1600 up to andincluding those highly siliceous material where the silica/alumina moleratio is infinity, or as reasonably close to infinity as practicallypossible. This latter group of highly siliceous materials is exemplifiedby U.S. Pat. Nos. 3,941,871; 4,061,724; 4,073,865 and 4,104,294 whereinthe materials are prepared from reaction solutions which involve nodeliberate addition of aluminum. However, trace quantities of aluminumare usually present due to the impurity of the reaction solutions. It isto be understood that the expression "high silica-containing crystallinematerial" also specifically includes those materials which have othermetals besides aluminum associated therewith, such as boron, iron,chromium, etc. Thus, the only requirements with regard to the startingmaterials utilized in the novel process of this invention is that theyhave a silica/alumina ratio greater than about 1600 (irrespective ofwhat other materials or metals are present in the crystal structure).

As is well known in the art, the concept of incorporating a crystallinesilicate including crystalline aluminosilicate zeolites with aninorganic oxide such as alumina, silica, titania, silica-alumina, etc.is well known in the art and these materials are broadly referred to asbinders or matrices. The binders and matrices serve very valuablefunctions, including imparting extra strength to the zeolitic catalysts,but strictly from a catalytic point of view they are not ascatalytically active as the zeolite with which they are admixed so thatthe total effect is that the catalytic activity of the composition hasbeen reduced. Thus, it is conventional in the prior art to use aninorganic oxide binder such as alumina with a zeolite such as ZSM-5 butthe resulting composition has less catalytic activity than would beobtainable by the use of the pure zeolite alone. Thus, quite simply put,the instant invention is not concerned with those crystalline silicateswhich have an inherently sufficiently high acid activity such thatincorporating them with alumina would result in obtaining a compositionwhich had less activity than the silicate material itself. Thisinvention is concerned with crystalline silicate materials which havesubstantially little or no acid catalytic activity as convenientlymeasured by the Alpha test. They have Alpha Values of less than about 5.This invention would reside in improving said acid catalytic activity.

Another way of expressing the same concept is to point out that in oneembodiment, the novel process of this invention involves the followingsteps: (1) mixing, such as by mulling, of a high silica zeolite with aninorganic oxide, such as alumina, and water, (2) forming or shaping, and(3) air calcining (e.g. in air) at elevated temperatures.

Optionally, the formed or shaped composition of step (2) is calcined ina non-oxidizing atmosphere, e.g. ammonia, at from about 900° F. to about1200° F. for at least about one hour, preferably for from about one hourto about five hours. Also optionally, the formed or shaped compositionof step (2) or the product of calcination thereof in a non-oxidizingatmosphere is treated with acidic cations, especially if the sodiumcontent of the material is greater than about 0.02 wt.%, in order toinsure less than 0.02 wt.% sodium content.

In short, the following list of steps will be followed by the presentmethod:

(1) mixing with inorganic oxide in pressure of water

(2) forming or shaping

(3) optionally calcining the formed or shaped composition in anon-oxidizing atmosphere

(4) optionally treating with acidic cations

(5) calcining

It appears obvious that for certain zeolites, steps (3), (4), and (5)will result in enhancing their catalytic activity without carrying outsteps (1) and (2). Thus, it is very well known in the art that baseexchange of the sodium in a crystalline zeolite with acidic ions, suchas ammonium ions, results in enhancing the acid activity of suchmaterial. As indicated earlier, this is because those materials containsufficient aluminum in the framework structure such that they must bebalanced by cations and base exchange with acidic ions allows theincorporation of a substantial amount of acidic cations into the crystalstructure, thereby resulting in enhanced activity.

Quite obviously, if the steps (1) and (2) were carried out with acrystalline material having these characteristics no enhancement inactivity would result, but rather, a dilution of activity would resultmerely because the inorganic oxide would dilute the acid activity of thefar more active zeolitic component.

As indicated earlier, the high silica crystalline materials with whichthis invention is concerned contain very small amounts of aluminum, withor without iron, chromium, boron, etc. It is difficult to set exactnumerical limits for the amount of such materials which the compositionmust contain in order to be operable within the novel process of thisinvention due to the fact that at such low levels analytical techniquesare not necessarily accurate. However, in order to give some indicationof the ranges of such content, it would be generally from about 50 to nomore than about 1000 ppm, preferably no more than about 500 ppm, i.e. asilica/alumina mole ratio of greater than about 1600.

As has previously been indicated, the novel method for the preparationof catalysts having enhanced acid activity according to this inventioninvolves carrying out at least three necessary steps. The firstnecessary step in the novel process of this invention involves (1)mixing, such as for example mulling, a crystalline silicate having ahigh silica/alumina mole ratio of greater than about 1600 and an AlphaValue of less than about 5 with an appropriate acidic inorganic oxide inthe presence of water. It is absolutely crucial that there be waterpresent during step (1) since it has been found that if the zeolite andthe inorganic oxide material is mixed, e.g. mulled, in a dry state thatsubstantially no activation will occur. The amount of water which isutilized is not narrowly critical and only enough water has to be usedto ensure an adequate mixture of the inorganic oxide and the high silicamaterial. The mixing can be carried out by hand with a mortar and pestleor commercially available mullers can be used. An example of suchmullers are those manufactured by the Cincinnati Muller Company ofCincinnati, Ohio.

The acidic inorganic binder which is used in step (1) is preferablyalumina or an alumina-containing material. However, other binders can beused such as titania and zirconia or mixtures of alumina, titania andzirconia. For reasons which are not completely understood, silica hasessentially no effect on the acid activity of the material and, thus,cannot be used by itself.

The amount of inorganic oxide which is incorporated with the high silicacrystalline material has a surprising effect on the acid activity of theresulting composition. The preferred range of inorganic oxide is, thus,20-95 wt.% based on total composition of inorganic oxide plus highsilica crystalline material.

The second necessary step in the novel process of this inventioninvolves a forming step (2) so as to obtain discrete particles of thecatalyst composite. The forming step includes simply sizing the materialto any appropriate size using any appropriate die or compacting typedevice, including hand pelleting. The forming step also includes spraydrying the step (1) mixture or using the oil-drop method. However, apreferred embodiment of this step is to use extrusion, i.e. to pass thecomposition of step (1) through a die at extremely high pressures, i.e.at pressures ranging from about 2 to about 50 t/in² or even higher,preferably higher than about 5 t/in². Typical extruders can be of thehydraulic ram type or of the bonnet auger type.

The third necessary step in the novel process of this invention involvescalcination, such as in air, at elevated temperature, i.e. temperaturefrom about 800°-1500° F. for periods of time ranging from about 2-5hours. A particularly preferred embodiment would be air calcination atabout 1000° F. for about three hours.

An optional step in the novel process of this invention involvescalcination of the step (2) product in a non-oxidizing atmosphere attemperatures from about 900°-1200° F. for at least about 1 hour, e.g.1-5 hours. The non-oxidizing atmosphere is preferably ammonia, althoughnitrogen and/or inert gases can be used.

A further optional step involves ion exchange of the composition withhydrogen ions or ammonium ions in order to reduce the sodium content toless than about 0.02 wt.%.

Of the high silica materials advantageously treated in accordanceherewith, those having the structure of zeolite ZSM-5, ZSM-5/ZSM-11intermediate or ZSM-11 are particularly noted. ZSM-5 is described inU.S. Pat. No. 3,702,886 and U.S. Pat. No. Re. 29,948, the entirecontents of each being incorporated herein by reference. ZSM-11 isdescribed in U.S. Pat. No. 3,709,979, the teaching of which is herebyincorporated by reference. ZSM-5/ZSM-11 intermediate is described inU.S. Pat. No. 4,229,424, the entire contents thereof being incorporatedherein by reference. Quite obviously, these materials must be used inthe manner previously indicated, i.e. having a silica/alumina mole ratioof greater than about 1600 and an Alpha Value of less than about 5.

The following examples will illustrate the best mode contemplated forcarrying out this invention.

EXAMPLE 1 Preparation of ZSM-5 containing about 50 ppm alumina (about38,000:1 silica-to-alumina ratio)

ZSM-5 crystals were synthesized from a formulation containingtetraethylorthosilicate, sodium hydroxide, tetrapropylammonium bromide,and water at 212° F. with intensive agitation. Special precautions weretaken to prevent alumina contamination from the crystallizationequipment and the environment.

A 50 g quantity of the material was calcined in an ammonia atmosphere at1000° F. for three hours to decompose the organic components in thezeolite. The product was pure white without any signs of a carbonresidue. The NH₃ calcined material was subsequently purged with nitrogenand then air for one hour to remove any absorbed NH₃. The sodium contentof the sample was reduced to 0.01 wt.% by treatment with a 0.1N ammoniumnitrate solution followed by hot water washing. The sample was thendried and its chemical composition was determined to be as follows:

    ______________________________________                                        Al.sub.2 O.sub.3, ppm                                                                        50                                                             SiO.sub.2, wt. %                                                                             >99                                                            Na, wt. %      0.01                                                           N, wt. %       <0.05                                                          C, wt. %       <0.03                                                          Ash, wt. %     99.6                                                           ______________________________________                                    

EXAMPLE 2

A portion of a zeolite produced in accordance with Example 1 wascalcined in a muffle furnace at 1000° F. for three hours, sized to 30-60mesh, and 2.5 g (4.8 cc) were charged to a 5/16" ID stainless steelmicroreactor. The ZSM-5 was treated in situ with hydrogen at 900° F. forone hour. Propylene, admixed with 50 volume percent of hydrogen, wasthen passed over the catalyst at 500 psig (total pressure-1000 psig),0.4 WHSV, 400° F. for two hours. No C₆ + liquid product was obtained.

EXAMPLE 3 Conversion of Propylene over a physical mixture of 50 ppm Al₂O₃ ZSM-5 and alumina

A mixture of 1.63 g (2.9 cc) 50 ppm Al₂ O₃ ZSM-5 plus 0.87 g (1.8 cc)alpha alumina monohydrate, both sized to 30-60 mesh and calcined at1000° F. for three hours, was charged to the reactor and treated againin situ with hydrogen at 1000° F. for one hour. Propylene was thenpassed over the catalyst under the same conditions as in Example 2 forsuccessive periods of 161/2 and 221/2 hours. Again, no C₆ + liquid wasformed.

EXAMPLE 4 Preparation of 50 ppm Al₂ O₃ ZSM-5 with 35 wt.% alumina binder

The 50 ppm Al₂ O₃ ZSM-5, as synthesized, was mulled with 35 wt.% alphaalumina monohydrate with added deionized water, extruded (1/16") at 25t/in² pressure, dired at 230° F., precalcined in ammonia for three hoursat 1000° F., ammonium exchanged to insure sodium content less than 0.02wt.%, dried at 230° F., and calcined in air for three hours at 1000° F.

EXAMPLE 5 Propylene Over 50 ppm Al₂ O₃ with 35 wt.% alumina binder

A 2.50 g quantity of the product from Example 4, sized to 30-60 mesh,was charged to the reactor, treated with hydrogen in situ for one hourat 900° F. Then propylene was passed over the catalyst under theconditions of Examples 2 and 3. Results are shown below:

    ______________________________________                                                         Yields                                                       ______________________________________                                        Material Balance Time,                                                                           191/2   22                                                 Hrs.                                                                          Time on Stream, Days                                                                             0.8     0.9                                                Yields, wt. %                                                                 C.sub.1 + C.sub.2  <0.1    <0.1                                               C.sub.3.spsb.=     22.7    22.7                                               C.sub.3            2.4     3.0                                                C.sub.4 's         1.2     1.4                                                C.sub.5 's         1.8     1.4                                                C.sub.6.spsb.+     71.9    71.4                                                                  100.0   100.0                                              ______________________________________                                    

The C₆ + liquid from the two runs was composited and distilled to give28.6 wt.% 330° F.⁻ gasoline and 42.9 wt.% 330° F.⁺ fuel oil. Thegasoline had an octane number (R+O) of 94 and the fuel oil a pour pointof less than -70° F., diesel index 67.

    ______________________________________                                                       330° F..sup.-  Gasoline                                 ______________________________________                                        Yield, wt. %     28.6                                                         Gravity, °API                                                                           64.7                                                         Gravity, specific                                                                              0.7213                                                       O.N., R + O      94                                                           Boiling Range, °F.                                                      5%              132                                                          50%              267                                                          95%              328                                                          ______________________________________                                    

    ______________________________________                                        330° F..sup.+  Distillate (Fuel Oil)                                   ______________________________________                                        Yield, wt. %     42.9                                                         Gravity, °API                                                                           42.7                                                         Gravity, specific                                                                              0.8123                                                       Pour Point, °F.                                                                         <-75                                                         Aniline No.      157.2                                                        Diesel Index     67                                                           Hydrogen, wt. %  13.93                                                        Carbon           86.15                                                        H/C Ratio        1.92                                                         Boiling Range, °F.                                                      5%              339                                                          50%              458                                                          95%              651                                                          ______________________________________                                    

EXAMPLE 6 Waxy Lube Raffinate Charge

A furfural extracted, waxy heavy neutral lube stock, designated Coryton0048 raffinate, was processed over the catalysts of Examples 1 and 4 at1 LHSV, 400 psig, 2500 SCF hydrogen/bbl. Results are compared below witha conventional ZSM-5 catalyst (1% Ni on 70/1 SiO₂ /Al₂ O₃ ZSM-5 with 35%alumina binder, steamed to an Alpha Value of 70).

    __________________________________________________________________________    Lube Dewaxing                                                                                     Mixture*                                                                      Example 1 +  Conventional                                 Catalyst            Al.sub.2 O.sub.3                                                                     Example 4                                                                           Catalyst                                     __________________________________________________________________________    Temperature, °F.                                                                           650    651   551                                          Material Balance Time, Hrs.                                                                 CHARGE                                                                              181/2  18    18                                           Yields, wt. %       LIQUID                                                    C.sub.1 + C.sub.2   PRODUCT                                                                              <0.1  0.1                                          C.sub.3                    0.9   2.2                                          C.sub.4                    2.5   3.8                                          C.sub.5                    1.8   2.1                                          C.sub.6 -650° F.    9.4   8.8                                          650° F..sup.+ Lube  85.1  82.8                                         650° F. Lube Properties                                                Gravity, °API                                                                        29.1         28.4  28.5                                         Gravity, specific                                                                           0.8811       0.8849                                                                              0.8844                                       Pour Point, °F.                                                                      >115  >115   +20   +10                                          KV @ 40° C., cs                                                                      --    --     95.08 109.0                                        KV @ 100° C., cs                                                                     9.91  --     10.77 11.42                                        V.I. --       --    96.3   90.0                                               __________________________________________________________________________     *Physical mixture of 1.7 g (3.0 cc) Example 1 plus 0.9 g (1.8 cc) alumina                                                                              

The 50 ppm Al₂ O₃ catalyst had essentially no lube catalytic dewaxingactivity. Addition of the alumina binder (Example 4) imparts activitywith no adverse effect on the ZSM-5 shape selectivity as indicated bythe pour point-viscosity index relationship. In this example it is lessactive but more selective than the standard conventional catalyst, i.e.gives a higher viscosity index at about the same pour point.

EXAMPLES 7-8

The following examples will illustrate that the use of zeolites having asignificant amount of alumina, i.e. a silica/alumina mole ratio of 1600or less, are not activated by the procedure of this invention, butrather, their activity is diluted.

EXAMPLE 7 70/1 SiO₂ /Al₂ O₃ ZSM-5 2.5 wt Al₂ O₃, 25,000 ppm

Propylene was passed over the 70/1 SiO₂ /Al₂ O₃ ZSM-5 catalyst, with andwithout 35% alumina binder under the same conditions as those used inExamples 2, 3 and 5. Results are listed below:

    ______________________________________                                                         35% Alumina Binder                                                            400                                                          ______________________________________                                        WHSV           0.6     0.4                                                    Material Balance                                                                             17      22.5                                                   Time, Hrs.                                                                    Yields, Wt. %                                                                 C.sub.1 + C.sub.2                                                                            0.1     0.1                                                    C.sub.3 =      1.2     2.0                                                    C.sub.3        1.9     3.1                                                    C.sub.4 's     0.9     0.4                                                    C.sub.5 's     1.3     0.6                                                    C.sub.6 +      94.6    93.9                                                                  100.0   100.0                                                  Liquid Product                                                                Boiling Range, °F.                                                      5%            246     221                                                    10%            314     266                                                    30%            453     368                                                    50%            539     446                                                    70%            604     525                                                    90%            733     641                                                    95%            786     709                                                    ______________________________________                                    

It can be seen that the catalyst without binder was actually more activethan that with binder, i.e. the liquid product had a higher boilingrange. The binder in this case "dilutes" the concentration of ZSM-5 andthus decreases the activity of a given weight of final catalyst.

EXAMPLE 8

In this example a ZSM-5 having a silica-to-alumina ratio of 1600:1(about 0.10 wt. % alumina, or 1,000 ppm) was used. The waxy luberaffinate of Example 6 was processed over this 1600/1 SiO₂ /Al₂ O₃ZSM-5, with and without 35% alumina binder. Conditions were again thesame as those used in that example.

    ______________________________________                                                           5% Alumina Binder                                                             650                                                        ______________________________________                                        Material Balance Time                                                                         19       18                                                   Hrs.                                                                          Yields, wt. %                                                                 C.sub.1 + C.sub.2                                                                             <0.1     0.1                                                  C.sub.3         1.6      2.1                                                  C.sub.4         2.9      5.0                                                  C.sub.5         1.8      2.7                                                  C.sub.6 -650° F.                                                                       10.7     13.7                                                 650° F.+ Lube                                                                          82.5     76.2                                                 650° F.+ Lube Properties                                               Gravity, °API                                                                          27.4     27.1                                                 Specific        0.8905   0.8922                                               Pour Point, °F.                                                                        -20      +10                                                  KV @ 40° C., cs                                                                        113.9    109.1                                                KV @ 100° C., cs                                                                       11.44    11.21                                                V.I.            84.6     86.2                                                 ______________________________________                                         *Physical mixture of ZSM5 plus alumina, alumina equal in weight to that       present in bound catalyst                                                

From the above example, it can be seen that a binder is not necessaryfor generation of an active catalyst at this alumina level, and in fact,the presence of alumina actually dilutes the activity of the catalystwithout the binder.

EXAMPLE 9

The procedure of Example 4 was repeated with the sole exception that nowater was used in mulling the alumina with a high silica ZSM-5.

EXAMPLE 10

In this example alumina alone was mulled with added water (no highsilica zeolite) and then the high silica zeolite of Example 2 was wettedwith the extract liquid and thereafter processed in identical manner toExample 2, i.e. ammonium precalcination for three hours at 1000°, baseexchanged with an ammonium solution to reduce the sodium content to 0.02wt. % followed by air calcination.

EXAMPLE 11

This example consisted of the use of 100% Kaiser alumina binder alone inorder to completely eliminate the possibility that alumina itself wasresponsible for any catalytic activity.

The catalysts of Examples 9, 10 and 11 were evaluated for the conversionof propylene under conditions recited in Examples 2 and 3 and theresults are shown in the following table together with results from someof the previously referred to examples.

                                      TABLE                                       __________________________________________________________________________    Conversion of Propylene                                                                        Physical      Wetted With                                                Pure Mixture                                                                              Dry-Mulled                                                                           H.sub.2 O Extract                                                                    Wet-Mulled                                                                            Alumina                                     Crystals                                                                           With Binder                                                                          With Binder                                                                          With Binder                                                                          With Binder                                                                           alone                           Example     2    3      9      10     4       11                              __________________________________________________________________________    WHSV, on total                                                                            0.4  0.6    0.6    0.6    0.5 0.6 0.5                             Material Balance                                                                          2    15     18     18     19.5                                                                              18.5                                                                              2                               Time, Hrs.                                                                    C.sub.3.sup.=  Conversion, wt %                                                           16   15     16     5      77  77  55                              Yields, wt. %                                                                 C.sub.1 + C.sub.2                                                                         0.1  0.5    0.1    --     --  0.3 --                              C.sub.3.sup.=                                                                             84.0 85.5   83.6   95.2   22.7                                                                              22.6                                                                              45.4                            C.sub.3     7.9  13.3   3.3    0.9    2.4 1.8 53.8                            C.sub.4 + C.sub.5                                                                         8.0  0.7    8.2    2.7    3.0 3.0 0.8                             C.sub.6.sup.+                                                                             0.1  0.1    4.8    1.1    71.9                                                                              72.3                                                                              --                                          100.0                                                                              100.0  100.0  100.0  100.0                                                                             100.0                                                                             100.0                           330° F.+ Distillate                                                                --   --     --     --     56  --  --                              % of Liq. Prod.                                                               __________________________________________________________________________

From the above table, the pure crystals, i.e. Example 2 made no liquidproduct. The physical mixture, i.e. Example 3, eliminated thepossibility that the high silica ZSM-5 and the alumina particles as suchare interacting and the dry mulling experiment, i.e. Example 9,eliminates ammonium exchange in the final calcination as being involvedin the generation of active sites. The water extract experiment, i.e.Example 10, eliminates room temperature wet mulling as a possible sourceof dissolved alumina entering the ZSM-5 pores. The alumina onlyexperiment, i.e. Example 11, also made no liquid product and as suchthis result confirms the fact that the binder as such in the wet mulledcatalyst is not making liquid product at 400° F.

EXAMPLES 12-14

Another series of examples were carried out in order to illustrate thecriticality of the use of water during the mulling of the high silicazeolite with the alumina. In all of these examples, 65 wt. % of theultra low alumina zeolite of Example 1 was used and the binder was 35wt. % alpha alumina monohydrate. Each sample was treated after formingin accordance with the procedure of Example 4. Examples 12 and 14 didnot use water. Example 13 did use water but no hydraulic pressure.

The compositions were evaluated together for Alpha activity.

As is known in the art, the Alpha Value is an approximate indication ofthe catalytic cracking activity of the catalyst compared to a standardcatalyst and it gives the relative rate constant (rate of normal hexaneconversion per volume of catalyst per unit time). The Alpha test isdescribed in U.S. Pat. No. 3,354,078 and in The Journal of Catalysis,Vol. IV, pp. 522-529 (August 1965).

The results are shown in the following table along with a comparisonwith the catalyst of Example 4.

                                      TABLE                                       __________________________________________________________________________    Example 12      13      14     4                                              __________________________________________________________________________    Method of                                                                             Dry Mulling.sup.(1)                                                                   Wet Mulling.sup.(1)                                                                   Dry Mixing.sup.(2)                                                                   Wet Mulling.sup.(1)                            Incorporation                                                                         and Hand                                                                              and Hand                                                                              and Hand                                                                             Hydraulic Extrusion                                    Pressing                                                                              Pressing                                                                              Pressing                                                                             (at 25 ton pressure (3)                        Alpha Activity                                                                        0.25    1.0     0.13   5.7                                            __________________________________________________________________________     .sup.(1) Mulling  Mix in a muller (Cincinnati Muller Co.) for 10-15           minutes with or without water                                                 .sup.(2) Mixing  Mechanical mixing with no kneading action                    (3) Extrusion  Extrusion using a hydraulic RAM extruder                  

As can be seen, the preparation without water, i.e. Examples 12 and 14,resulted in very low Alpha Values--even though the ammoniaprecalcination, ammonium exchange and air calcination were carried out.However, the preparations with water gave enhanced results.

EXAMPLES 15-16

Examples 15 and 16 illustrate the effect of time and temperature ofammonia precalcination on alpha activity and a comparison is made withthe catalyst of Example 4. In each of Examples 15 and 16, the procedureof Example 4 was followed.

The results and operation conditions are shown in the following table.

                  TABLE                                                           ______________________________________                                        Example       15          4      16                                           ______________________________________                                        Precalcination                                                                Temperature, °F.                                                                     800         1000   1200                                         Time, Hr.      8            3      3                                          Atmosphere    NH.sub.3    NH.sub.3                                                                             NH.sub.3                                     Alpha Activity                                                                              0.5         5.7    3.0                                          ______________________________________                                    

EXAMPLES 17-18

Examples 17 and 18 show the effect of binder concentration onactivation.

In each of Examples 17 and 18 the exact procedure of Example 4 wasfollowed with the exception of varying the binder content. Note that thebinder has a surprising effect on activity.

The results and specific formualtions are shown below together with thecatalyst of Example 4.

                  TABLE                                                           ______________________________________                                        Example      17          4       18                                           ______________________________________                                        Zeolite/Binder                                                                             90/10       65/35   10/90                                        (wt. basis)                                                                   Alpha activity                                                                             0.40        5.7      3.0                                         Alpha activity,                                                                            0.24        5.7     19.5                                         Normalized*                                                                   ______________________________________                                         *Normalized to unit weight of zeolite based on 65/35 wt. ratio.          

EXAMPLES 19-22

These examples show that ZrO₂ and TiO₂ as binder material impartsignificant Alpha activity compared to Al₂ O₃, using mortar and pestlemixing and pressing as the method of incorporation (insufficientmaterial for hydraulic extrusion). SiO₂ as a binder has essentially noeffect on Alpha activity.

Details of the preparation of these materials are described below.

EXAMPLE 19 Zirconia Binder

As synthesized ultra low Al ZSM-5 zeolite was intimately mixed with azirconia gel of 25% solution by weight (from duPont Chemical). Theweight ratio of ZSM-5 to ZrO₂ was adjusted to 65/35. The mixture wasthen dried and calcined in a NH₃ stream at 1000° F. for three hours. TheNa content in the material was then exchanged with 1N NH₄ /NO₃ solutionto reduce to less than 0.05%. The sample was then sized to 14/25 meshsize material and calcined to 1000° F. in air for three hours.

EXAMPLE 20 Titania Binder

Preparation procedure and catalytic test method of the catalyst aresimilar to that in Example 19 except that 25% titania gel (from duPontChemical) was used instead of ZrO₂ gel.

EXAMPLE 21 Silica Binder

Preparation procedure and catalytic test method of the catalyst aresimilar to that in Example 19 except that 30% colloidal SiO₂ (fromduPont Chemical) was used instead of ZrO₂ gel.

EXAMPLE 22 Alumina Binder

Same as Example 19, except Kaiser alpha alumina monohydrate was used.

The results are shown in the following table together with the resultsobtained with the composition of Example 1.

                  TABLE                                                           ______________________________________                                        Example   19       20      21    22     1                                     ______________________________________                                        Binder Material                                                                         ZrO.sub.2                                                                              TiO.sub.2                                                                             SiO.sub.2                                                                           Al.sub.2 O.sub.3                                                                     None                                  Zeolite/Binder                          Pure                                  (wt. basis)                                                                             ← 65/35 → Zeolite                                       Method of Mortar and Pestle Mix and Hand Pressing                             Incorporation                                                                 Alpha Activity                                                                          0.72     0.77    0.28  0.51   0.2                                   ______________________________________                                    

EXAMPLES 23-25

These examples illustrate that the mesh size of the catalyst is notcritical.

In each of Examples 23-25, the catalyst prepared by the process ofExample 4 was ground to different mesh size and the Alpha activitymeasured.

The results are shown in the following table.

                  TABLE                                                           ______________________________________                                        Example        23         24      25                                          ______________________________________                                        Mesh Size of Catalyst                                                                        12-14      14-25   25-40                                       Alpha Activity 5.8        5.7     5.2                                         ______________________________________                                    

EXAMPLE 26

To further demonstrate the present invention, a 2 gram quantity ofcalcined product from Example 4 is placed in a reactor vessel andcontacted with a feedstock comprised of 80% m-xylene and 20%ethylbenzene in the presence of added hydrogen at a ratio ofhydrogen/hydrocarbons of 6.5/1. At reaction conditions including atemperature of 428° C., 58.5 WHSV (hr⁻¹) and a pressure of 10.2atmospheres, approximately 52% of the m-xylene and 51% of theethylbenzene are converted. The product is comprised as follows, valuesapproximate:

    ______________________________________                                        Product Component Wt. %                                                       ______________________________________                                        Benzene           4.0                                                         Toluene           0.8                                                         Ethylbenzene      9.3                                                         p-Xylene          17.7                                                        m-Xylene          39.4                                                        o-Xylene          18.1                                                        Ethyltoluenes     1.0                                                         Trimethylbenzenes 2.7                                                         Other             7.0                                                         ______________________________________                                    

What is claimed is:
 1. A process for converting feedstock comprisingaromatic compounds selected from the group consisting of benzene,toluene, ethylbenzene and mixtures thereof to alkylation conversionproduct comprising aromatic compounds which differs from said feedstock,which comprises contacting said feedstock and an alkylating agent atconversion conditions sufficient to convert said feedstock to saidproduct with a catalyst composition prepared by a method for enhancingthe acid activity of a high silica-containing crystalline zeolitecontaining from about 50 ppm to less than about 1000 ppm alumina andhaving an Alpha Value of less than about 5, which method comprises thesteps of:(1) mulling said zeolite with an acidic inorganic oxideselected from the group consisting of alumina, zirconia, titania andmixtures thereof in the presence of water, (2) forming or shaping thecomposition of step (1) into a desired shape at a pressure of from about2 to about 50 tons per square inch, (3) calcining the formed or shapedcomposition of step (2) in a non-oxidizing atmosphere at from about 900°F. to about 1200° F. for from about 1 hour to about 5 hours, (4)treating said calcined composition from step (3) by base exchange if thesodium content thereof is greater than about 0.02 wt % in order toreduce the sodium content thereof to less than about 0.02 wt %, and, iftreated, (5) calcining said treated composition of step (4) at elevatedtemperature.
 2. The process of claim 1 wherein the composition of methodstep (1) comprises from about 20 to about 95 wt % acidic inorganicoxide.
 3. The process of claim 1 wherein method step (2) is carried outat a pressure greater than 5 tons per square inch.
 4. The process ofclaim 1 in which the zeolite has the structure of ZSM-5, ZSM-5/ZSM-11intermediate or ZSM-11.
 5. The process of claim 4 in which the zeolitehas the structure of ZSM-5.
 6. The process of claim 1 wherein thenon-oxidizing atmosphere of method step (3) comprises ammonia.
 7. Theprocess of claim 1 wherein said conversion conditions include atemperature of from about 340° C. to about 500° C., a pressure of fromabout atmospheric to about 200 atmospheres, a weight hourly spacevelocity of from about 2 hr⁻¹ to about 2000 hr⁻¹ and an aromatichydrocarbon/alkylating agent mole ratio of from about 1/1 to about 20/1.8. The process of claim 1 wherein said alkylating agent is selected fromthe group consisting of olefins, formaldehyde, alkyl halides and alkylalcohols, alkyl having from 1 to 24 carbon atoms.
 9. The process ofclaim 8 wherein alkyl is methyl or ethyl.
 10. A process for convertingfeedstock comprising aromatic compounds selected from the groupconsisting of benzene, toluene, ethylbenzene and mixtures thereof toalkylation conversion product comprising aromatic compounds whichdiffers from said feedstock, which comprises contacting said feedstockand an alkylating agent at conversion conditions sufficient to convertsaid feedstock to said product with a catalyst composition prepared by amethod for enhancing the acid activity of a high silica-containingcrystalline zeolite containing from about 50 ppm to less than about 1000ppm alumina and having an Alpha Value of less than about 5, which methodcomprises the steps of:(1) mulling said silicate with alpha aluminamonohydrate in the presence of water to form a wet composite mixture,(2) extruding the wet mixture of step (1) at a pressure of from about 2to about 50 tons per square inch to form discrete composite particles,(3) calcining the discrete composite particles of step (2) in anon-oxidizing atmosphere at a temperature of from about 900° F. to about1200° F. for at least one hour, (4) treating the calcined compositeparticles of step (3) with hydrogen or ammonium cations if the sodiumcontent thereof is greater than about 0.02 wt % and, if treated, (5)calcining the treated composite particles of step (4) at elevatedtemperature.
 11. The process of claim 10 wherein the composition ofmethod step (1) comprises from about 20 to about 95 wt % alpha aluminamonohydrate.
 12. The process of claim 10 wherein method step (2) iscarried out at a pressure greater than 5 tons per square inch.
 13. Theprocess of claim 10 in which the zeolite has the structure of ZSM-5,ZSM-5/ZSM-11 intermediate or ZSM-11.
 14. The process of claim 13 inwhich the zeolite has the structure of ZSM-5.
 15. The process of claim10 wherein the non-oxidizing atmosphere of method step (3) comprisesammonia.
 16. The process of claim 10 wherein said conversion conditionsinclude a temperature of from about 340° C. to about 500° C., a pressureof from about atmospheric to about 200 atmospheres, a weight hourlyspace velocity of from about 2 hr⁻¹ to about 2000 hr⁻¹ and an aromatichydrocarbon/alkylating agent mole ratio of from about 1/1 to about 20/1.17. The process of claim 10 wherein said alkylating agent is selectedfrom the group consisting of olefins, formaldehyde, alkyl halides andalkyl alcohols, alkyl having from 1 to 24 carbon atoms.
 18. The processof claim 17 wherein alkyl is methyl or ethyl.